You cited the article which dealt with the 1990-91 conflict.
It's obvious to anybody who reads that the Georgian refusal to let South Ossetia go with North Ossetia when the USSR broke up is the main origin of the current friction.
If you don't believe this, exactly why not?
The answer to your question is also painfully obvious--South Ossetians have far more in common with North Ossetians than with Georgians.